Chlorocarbonylsulfenyl chloride

Several related derivatives have also been utilized in this type of synthesis. Imino-chloromethanesulfenyl chlorides (184), prepared by the controlled addition of chlorine to isothiocyanates, react with amidines (161) to give 1,2,4-thiadiazolines (185) (71T4117). Chlorocarbonylsulfenyl chloride (186), prepared by the hydrolysis of trichloromethanesulfenyl chloride with sulfuric acid, reacted with ureas, thioureas and guanidines to give 1,2,4-thiadiazolidine derivatives (187) <70AG(E)54, 73CB3391). 

The reaction of O-ethyl carbamate 70 with chlorocarbonylsulfenyl chloride 71 affords a mixture of either 3-ethoxy-... 

Amidines and cyclic amidines are also converted into 1,2,4-thiadiazoles by reaction with isothiocyanates, imino-sulfenyl chlorides, di- and trichloromethyl sulfenyl chlorides, and carbon disulfide in the presence of sulfur. Ureas, thioureas, guanidines, carbodiimides, and cyanimides react with chlorocarbonylsulfenyl chloride to produce 1,2,4-thiadiazol-5-one derivatives in another example of a type B synthesis <1996CHEC-II(4)307>. 

Chloro-l,2,4-thiadiazolin-5-ones can be prepared by reacting chlorocarbonylsulfenyl chloride with carbodiimides or cyanamides (see Section 5.08.9.3). 

The reaction of 2-aminobenzothiazoles and chlorocarbonylsulfenyl chloride, with or without amines as catalyst, provides a new entry to the synthesis of [l,2,4]thiadiazolo[3,4- ]benzothiazol-3(3/7)-ones <1997H(45)1579> in modest yields. In the best example, 6-methyl-2-aminobenzothiazole 413 gives the target molecule 414 in 40% yield without adding any base (Equation 86). 

Nagai et al. carried out various transformations with camphor-fused amino[l,2,4]triazine 191 <1998JHC293> (Scheme 39). Reaction of 191 with chlorocarbonylsulfenyl chloride yielded the fused thiadiazolone 192 in high yield (83%). The same starting compound also proved to be suitable for the synthesis of the fused triazole derivative 193. To this end, 191 was first subjected to two subsequent transformations first by dimethylformamide dimethylacetal followed by treatment with hydroxylamine hydrochloride to give an Ar-hydroxyamidine 193 in 90% overall yield, and then this compound was treated with polyphosphoric acid to yield the fused triazole product 194 in 92% yield. 

The bifunctional chlorocarbonylsulfenyl chloride, obtainable through partial hydrolysis of trichlorotnethanesulfenyl chloride (162), is fluorinated by SbFg at the carbonyl group (66, 67) ... 

Cyclic amidines (213) react with chlorocarbonylsulfenyl chloride to give bicyclic 1,2,4-thia-diazoles. The product isolated from this reaction depends on the mode of addition. When (213) is added to chlorocarbonylsulfenyl chloride, 3-oxo derivatives (214) are isolated via the postulated intermediate (215). Addition of chlorocarbonylsulfenyl chloride to (213) leads to 5-oxo derivatives (216), via the proposed bis(intermediate) (217) (Scheme 47) <84CHEC-I(6)463). Cyclic amidines (213) have also been treated with 1-chloro-l-phenyliminomethanesulfenyl chloride (210) to afford 2>H-1,2,4-thiadiazoles (218). The other possible product from this reaction, the 2/7-isomer (219) has been shown to be unstable, rearranging to a benzothiazole. Heterocycles (213) which have been used in this transformation include 2-aminopyridine, 3-aminopyridazine, 2-aminobenzothiazole, 2-aminopyrimidine and 2-aminothiazole (Equation (33)) <86S1027>. 

A useful method for the synthesis of 5-chloro-l,2,4-thiadiazoles (206) is the reaction of amidines with trichloromethylsulfenyl chloride (see Equation (30)). 3-Halo derivatives (349) (X = Cl, Br, I) (Equation (57)) have been obtained in moderate yields from the corresponding amines (348) via the Sandmeyer-Gatterman reaction <84CHEC-I(6)463>. 3-Chloro-l,2,4-thiadiazolin-5-ones (350) and (351) can be prepared by reacting chlorocarbonylsulfenyl chloride with carbodiimides or cyanamides respectively (Scheme 79) <84CHEC-I(6)463>. 

Oxathiazoles and dithiazoles with exocyclic conjugation have also been obtained from appropriately substituted sulfenyl chlorides and carboxamides as detailed in Scheme 46. Part of the chlorocarbonylsulfenyl chloride chemistry has been reviewed <70AG(E)54>. 

The reaction of trichloromethanesulfenyl chloride (440) with amidines (439) and mild base is a general preparation for 5-chloro-l,2,4-thiadiazoles (441) (65AHC(5)119). Iminochloromethanesulfenyl chlorides (442 from RNCS + C12) react with amidines such as PhC(NH)NHR to give 1,2,4-thiadiazo-lines (443) (71T4117). Chlorocarbonylsulfenyl chloride (444) (prepared from trichloromethanesulfenyl... 

Chlorocarbonylsulfenyl chloride (291) also condenses with a variety of ureas, thioureas, guanidines, carbodiimides and cyanamides to produce l,2,4-thiadiazol-2-one derivatives of types (298), (297) and (299) as indicated in Scheme 106 (70AG(E)54, 73CB3391). 

Azine approach. The fused pyrimidines can be synthesized in the same way as the pyridines, e.g. by the cyclization of vicinal aminothiocyanates (70JCS(C)2478>. Another useful method for aminoazines is the reaction with chlorocarbonylsulfenyl chloride, e.g. with the aminopyrimidine (440) (73LA1018). The reaction can be rationalized by initial acylation of the amino group which is then cyclized with formation of the 2(3//)-one (441). Another case is the reaction of the 6-aminouracil (442) with thionyl chloride (69JOC3285). The reaction is rationalized as an initial electrophilic substitution at the 5-position of the activated pyrimidine. Subsequently the chlorosulfinyl derivative (443) is cyclized to a thiazoline S-oxide which loses water to yield the thiazole. 

Chloroacetaldehyde oxime, 2-carbon cyclization using, 55, 287 N-Chloroamides, chlorinating agents for pyrroles, 57, 326 N-Chloroamines radical cyclizations from, 58, 19 radicals by photolysis of, 58, 10 Chlorocarbonylsulfenyl chloride, reaction with 5-aminouracils, 55, 153 Chlorodimethylsulfonium chloride,... 

Unfortunately, introduction of the N-Dts group requires two steps, the first being reaction of the amino group with 0-ethyl S-carboxy methyl dithiocarbon-ate or 0,0-diethyl trithiodicarbonate [Scheme 8.20].32 The intermediate ethoxy-thiocarbonyl derivative is then treated with chlorocarbonylsulfenyl chloride, whereupon chloroethane is extruded to give the JV-Dts derivative. Since the first step is often accompanied by some noisome minor products, a solid-phase variant has been developed for the synthesis of N-Dts-protected amino acids.33... 

Oxo-1,3-oxathiolanes arc obtained from f(-o o esters or 1,3-diketoncs when treated with chlorocarbonylsulfenyl chloride at 80-100 Finally, hctcrocycles containing phosphorus have also been synthesized by substitution reactions, forming a C-O bond. ... 

Furthermore, 6-aminouracils are attacked by oxalyl chloride, diketene, and chlorocarbonylsulfenyl chloride at C-5, followed by cyclization with the amino group to give pyrrolo[2,3-[Pg.153]

Chloromethyl-2(3J7)-benzothiazolones were prepared from (94) and chlorocarbonylsulfenyl chloride (Scheme 21) <88S482>. 

The single example of this class that is known so far (555) has been synthesized as a stable precursor for the thermolytic in situ production of the allonoylnitrile A -sulfide 556 the latter is the reactive species in the synthesis of isothiazole (Section XI Scheme 149) and 1,2,4-thiadiazole C-nucleosides (Section XIX Scheme 203). The 5-(tri-0-benzoyl-/3-D-ribofuranosyl)-l,3,4-oxathiazol-2-one (780) was obtained from the 2,5-anhydro-D-allonic acid amide 779 by heating with chlorocarbonylsulfenyl chloride (84JOC2165 91MI21) (Scheme 213). 

The l,2,4,5-dithiadiazin-3-one 131 was prepared from thiohydrazide 221 by treatment with chlorocarbonylsulfenyl chloride in toluene at room temperature (Equation 21) <2003PS1283>. On heating, the product can eliminate a sulfur atom (see Section 9.14.6). 

Dithiadiazines. (1) Oxidative cyclization of l,6-diphenyl-2,5-dithiobiurea (Equation 14) (2) oxidative cyclization of A, A -dicarbethoxy-A, A -bis(mercaptomethyl)hydrazine (Scheme 32) (3) condensation of an oxamic acid thiocarbazide with chlorocarbonylsulfenyl chloride (Equation 21) (4) condensation of thiosemicarbazide derivatives with A -phenyl-3 -chloroisothiocarbamoyl chloride (Equation 22). Method (4) is the most general of these, provides good yields, and precursors are reasonably accessible. 

Chlorocarbonylsulfenyl chloride added to a soln. of l,3,5-triphenyl-perhydro-l,3,5-triazine in dichloromethane at room temp, with stirring, after 2 h AICI3 added portionwise, and stirred vigorously for 10 h at room temp. - 3-chloromethyl-2(3 )-benzothiazolone. Y 59%. The method is quick and cheap. F.e.s. Y. Tanabe, Y. Sane-mitsu. Synthesis 1988, 482-3. 

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